• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.581-586
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• 2002

The development of 2-D radiometer is a new technical challenge for space borne remote sensing area. The Y-type antenna array has been proposed as a most efficient configuration because a large alias free FOV and a small-synthesized beam-width can be achieved compared to L-, T-type under the fixed antenna spacing. New configuration of antenna array, which is called sub-Y type configuration, is proposed to obtain a higher angular resolution than the case of Y-type array in the paper. The sub-Y type array is consisted of basic arrays, which are the Y-type array of four antenna elements. To analyze characteristics of the proposed configuration, the synthesized beam pattern is simulated through simulation. The secondary effect of the sub-Y-type is that the reconstructed image is suffered from the alias effect is appeared around the real target. The ghost targets in the reconstructed image can be reduced by the alias suppression algorithm introduced in this paper. In conclusion, the performance evaluation by use of array factor simulation shows more than 37.5% improvement in average for angular resolution and almost similar performance for temperature resolution.

• 대한건축학회논문집:계획계
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• 제34권10호
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• pp.83-94
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• 2018

In many theoretical and empirical studies on the design issues of therapeutic healthcare facilities, spatial configuration that promotes users' wayfinding behavior, has been emphasized as a significant factor to mitigate stressful experiences and to enhance restorative quality in the healthcare environment. This is also applicable to the healthcare setting for children. However, not much evidence has been reported with regard to the relationship between spatial configuration and wayfinding behaviors in this specific setting. Moreover, healthcare facilities for children with physical disabilities need more attention to provide easy wayfinding due to various physical restrictions. The aim of this study is therefore, to unfold the relationship between spatial configuration and visual cognitive qualities of outpatient spaces in the selected children's rehabilitation hospitals in Seoul, by examining visual cognitive attributes such as visibility, accessibility, and intelligibility. In the first phase, the spatial layout of the hospitals was analyzed, with an emphasis on the major outpatient areas such as the entrance lobby, doctors' examination, and physical therapy zones. In the second phase, a space syntax tool was implemented to examine visual cognitive characteristics of the spatial configuration. The spatial configuration parameters measured were integration, integration core, visual isovist field continuity, correlation between integration and step depth, and the correlation between integration n and integration 3. As a result, the integration was higher in the hall type configuration. Circulation intersections acted mostly as integration cores for better visibility. Some areas showed the lack of continuity in the visual isovist fields overlap and irregular correlation between integration and step depth. The intelligibility was higher in the circulation area and social interaction spaces such as a cafe, reception waiting, and therapy waiting areas. Based on the analysis, design implication and possible future improvement were discussed to enhance wayfinding experiences in the hospitals for children with physical disabilities.

• 대한기계학회논문집A
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• 제25권4호
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• pp.619-628
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• 2001

A viscoelastic constitutive equation of rubber is proposed under small oscillatory load superimposed on large static deformation. The proposed model is derived through linearization of Simos nonlinear viscoelastic constitutive model and reference configuration transformation. Statically pre-deformed state is used as reference configuration. The model is extended to a generalized viscoelastic constitutive equation including widely-used Mormans model. Static deformation correction factor is introduced to consider the influence of pre-strain on the relaxation function. The model is tested for dynamic behavior of rubbers with different carbon black fractions. It is shown that the constitutive equation with static deformation correction factor agrees well with test results.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2005년도 추계학술대회 논문집
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• pp.311-314
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• 2005

Our city structure is being complicated from the development of industry and the increase in population. It makes the ground space overcrowded, so underground space is systematized for use. Because this underground space has very complicated configuration, people have difficulty in finding the route in the underground space. Therefore It is demanded to comprehend configuration of the various space structure, predict pattern of the moving and analyze induction factor of the moving. When people are in the conflagration or dangerous situation, they are in the habit of using the route which they are used to go to and from. It is needed to analyze moving pattern of the pedestrian who usually use the underground space for the sake of dealing with conflagration in the underground space. Finally, this study suggested that general characteristic, distribution, moving route of the pedestrian and factors influencing that they choose the route which the research finds out.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.362-365
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• 1999

In this paper, the method of reducing harmonics and correcting of power factor in single PWM converter associated with diode rectifier and boos converter is studied. The ac-dc converter in which the harmonic distortion in the input current is reduced using a third harmonic injected PWM is proposed. A lower switching power loss and easy configuration o control circuit are obtained by adopting discontinuous current mode. Simulation and experimental results of ac-dc converter with 5[KHz] switching frequency are presented and correction of power factor and reduction of total harmonic distortion was established.

• 대한기계학회논문집A
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• 제25권4호
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• pp.734-740
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• 2001

In this paper the stress intensity factor under uniform pressure in the arbitrarily-shaped plane crack configuration transformed elliptic crack by Mobius mapping are determined. Using Dysons formula Boussinesq-Papkovich potentials for mode I deformation are constructed. In the example the stress intensity factors are approximately calculated by least square method.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.117-122
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• 2000

In this paper the stress intensity factor under uniform pressure in the arbitrarily-shaped plane crack configuration transformed elliptic crack by Mobius mapping are determined. Using Dyson's formula Boussinesq-Papkovich potentials for mode I deformation are constructed. In the example the stress intensity factors are approximately calculated by least square method.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2003년도 The Fifth Asian Computational Fluid Dynamics Conference
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• pp.166-166
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• 2003

• 항공우주시스템공학회지
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• 제9권2호
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• pp.34-40
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• 2015

Staged combustion cycle engines are well known to have high combustion efficiencies and specific impulse. In this study, design of mixing head part of combustion chamber for 8tonf class staged combustion cycle rocket engine (ES-08) was performed. Structural stability of the mixing head part of the combustion chamber is very important design factor because it is loaded by high temperature and high pressure of fuel and oxidizer as well as by thrust load simultaneously. Uniformity of flow distributions of the propellants to the injectors is also important factor. First, a basic configuration for the ES-08 mixing head part was designed on the basis of the structural design requirements. And then, the structural analyses were performed on the basic configuration as well as some of reinforced configurations. As the structural analyses results, the most stable configuration was selected for the ES-08 mixing head part. In order to examine the uniformity of the flow distributions of the propellants through the manifold of the mixing head, flow analysis was performed based on the selected configuration. The results of the flow analysis showed that the fuel and the oxidizer were uniformly supplied to the injector.

• 대한기계학회논문집
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• 제13권4호
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• pp.771-779
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• 1989

본 연구에서는 기판의 양면에 부품이 SMT방법으로 탑재되어 있는 경우에 기판사이에 형성되는 유동채널에서의 열전달 및 유동특성을 연구하였다.